Has my pocket money kept up with inflation?

AI SLAA SLAI HL Accessible Also in: Statistics

Research question

What is the real value of my pocket money (or a part-time wage) over the last ten years, and would indexing it to a student-relevant basket of prices give a different answer from the official inflation index?

Adapt it: change the place, the data or the comparison until the question is yours.

Why it makes a good exploration

Inflation is abstract until it shrinks your own money. Building your own price index for things students buy — and comparing it with the official one — makes this very personal.

The mathematics you'll need

Percentage change and compound growth
Price indices and weighted means
Real vs nominal values
Exponential models of prices

Course labels show where a technique sits; using maths from outside your course is fine if you explain it clearly and say it is new to you.

Where the data comes from

Official consumer price index series; prices of items you buy from receipts, archived menus or published average prices.

Office for National Statistics (UK) — UK population, earnings, inflation, births and deaths time series.
Eurostat — EU statistics by country and region (prices, energy, transport, education).
FRED (Federal Reserve Bank of St. Louis) — 800,000+ economic time series (interest rates, inflation, unemployment) with CSV download.

Cite every source in a footnote where you use it and in your bibliography. Check the licence of any dataset you download.

A possible outline

Explain how an official price index is built.
Compute the real value of your money over time.
Build a student basket with justified weights.
Compare the two indices.
Reflect on substitution and quality changes.

Pitfalls that cost marks

Weights with no justification.
Comparing prices from different shops or sizes.
Confusing percentage points with percentages.

Showing personal engagement

Use your own spending records.
Survey classmates to set basket weights.
Negotiate a pocket-money rise using your model (and report the result).

See Criterion C: personal engagement for what examiners look for.

Taking it further

Fit exponential models to each item's price and compare their growth rates.

Turn this idea into your IA

Plan this IAOpens the planner with this question, the maths and data sources filled in. Desmos workspacePlot your data, fit models and keep your graphs with your plan. AI feedback on a draftCriterion-by-criterion feedback with evidence from your own text. Coaching, not rewriting. Examiner reviewPete, a practising IA examiner, reads your draft and talks it through with you (€100).